Warning: gigantic spoilers for the eighth episode of Agents of S.H.I.E.L.D. Season 5, called "The Last Day."
Agents of S.H.I.E.L.D. Season 5 has gone in some wild directions since sending most of the characters 74 years into the future to save the remnants of humanity after the Earth was destroyed and the Kree took over. The story only got more complicated with the introduction of Robin as a seer whose Inhuman abilities enable her to see the past, the present, and the future in one big jumble. In last week's episode, Robin turned up on what was left of the Earth to greet May warmly. This week, Robin's visions may have teased the death of at least one major character.
Robin revealed to May early in the episode that the last time anybody ever saw the full group -- that is, Coulson, May, Daisy, Fitz, Simmons, Mack, and Yo-Yo -- together was when they were in the diner right before the crazy Season 4 cliffhanger. This particular prophecy indicates that at least one of the group will die and/or be left behind when the rest of them return to 2017. Robin's prophecies have been on point so far, and Fitz has maintained all along that certain aspects of time can't possibly be changed. Agents of S.H.I.E.L.D. may very well be planning on killing somebody (or somebodies) off, and "The Last Day" may have dropped some hints about the characters most likely to bite the dust.
"The Last Day" gave glimpses into the future via Robin's visions, and they established several characters as alive, if not entirely well. May was with Robin all along, protecting her and eventually becoming her surrogate mother. Simmons was quickly revealed to be alive post-apocalypse on the Zephyr as well. Another vision confirmed that Fitz was around (and wearing a wedding band), frustrated and certain that trying to figure out time travel was a waste. He and Robin weren't getting along very well, especially once Robin evidently described Simmons' death to him. Still, these three characters survived.
Another vision confirmed that Yo-Yo was alive, although not at all happy that May had agreed to the terms of the Kree in order to survive. Daisy's presence back in 2017 was established a different way. When the other survivors in the Zephyr circa 2091 decided that killing Daisy before she could go back in time and destroy the world, one of the men showed her a video proving that she was present in the past.
The two characters whose fates are currently in question are Coulson and Mack. In the vision showing a confrontation between Yo-Yo and May, Yo-Yo was carrying Mack's beloved shotgun axe and reminded May that Mack was "gone." She didn't explicitly state that Mack was dead, but her tone and expression indicated that something terrible had happened to him. We didn't get any clues quite that strong about Coulson. Nevertheless, his absence in all of Robin's visions was notable. Even if nobody commented that Coulson was dead and gone, he would have undoubtedly been in the thick of the action alongside May if he was able.
Technically, Daisy's fate is somewhat up in the air as well. While she was present in the post-2017 timeline, she was never seen again after leaving the Zephyr and (supposedly) quaking the world apart. Daisy may have died in the same incident that destroyed the planet and doomed billions of people all over the world. Basically, we should probably start worrying about Daisy, Coulson, and especially Mack. Could the Agents of S.H.I.E.L.D. producers be so cruel as to kill Mack so soon after he was reunited with his shotgun axe?
Of course, there's every chance that Agents of S.H.I.E.L.D. will pull a fast one and simply rewrite the past in which the agents were never seen together again after they were yanked apart in the diner. Time travel is unpredictable, and S.H.I.E.L.D. never really established rules for its version of time travel. Besides, Robin's death at the end of "The Last Day" means that the agents won't be able to get any clarification on her prophecies. Everybody might live; it's just not exactly a sure thing.
We'll have to wait and see. New episodes of Agents of S.H.I.E.L.D. air on Fridays at 9 p.m. ET on ABC.